Support resource_name on AttachmentProcessor (#5205)

Contributes to #5198
Relates to elastic/elasticsearch#64389

Author: stevejgordon

src/Nest/Ingest/Processors/Plugins/AttachmentProcessor.cs

@@ -21,12 +21,12 @@ namespace Nest
 	[InterfaceDataContract]
 	public interface IAttachmentProcessor : IProcessor
 	{
-		/// <summary> The field to get the base64 encoded field from </summary>
+		/// <summary> The field to get the base64 encoded field from.</summary>
 		[DataMember(Name ="field")]
 		Field Field { get; set; }
 
 
-		/// <summary> If `true` and `field` does not exist, the processor quietly exits without modifying the document </summary>
+		/// <summary> If `true` and `field` does not exist, the processor quietly exits without modifying the document.</summary>
 		[DataMember(Name ="ignore_missing")]
 		bool? IgnoreMissing { get; set; }
 
@@ -37,20 +37,26 @@ public interface IAttachmentProcessor : IProcessor
 		[DataMember(Name ="indexed_chars")]
 		long? IndexedCharacters { get; set; }
 
-		/// <summary> Field name from which you can overwrite the number of chars being used for extraction. </summary>
+		/// <summary> Field name from which you can overwrite the number of chars being used for extraction.</summary>
 		[DataMember(Name ="indexed_chars_field")]
 		Field IndexedCharactersField { get; set; }
 
 		/// <summary>
 		/// Properties to select to be stored. Can be content, title, name, author,
-		/// keywords, date, content_type, content_length, language. Defaults to all
+		/// keywords, date, content_type, content_length, language. Defaults to all.
 		/// </summary>
 		[DataMember(Name ="properties")]
 		IEnumerable<string> Properties { get; set; }
 
-		/// <summary> The field that will hold the attachment information </summary>
+		/// <summary> The field that will hold the attachment information.</summary>
 		[DataMember(Name ="target_field")]
 		Field TargetField { get; set; }
+
+		/// <summary> The field containing the name of the resource to decode.
+		/// If specified, the processor passes this resource name to the underlying
+		/// Tika library to enable 'Resource Name Based Detection'.</summary>
+		[DataMember(Name = "resource_name")]
+		Field ResourceName { get; set; }
 	}
 
 	/// <inheritdoc cref="IAttachmentProcessor" />
@@ -75,6 +81,9 @@ public class AttachmentProcessor : ProcessorBase, IAttachmentProcessor
 		/// <inheritdoc cref="IAttachmentProcessor.TargetField" />
 		public Field TargetField { get; set; }
 
+		/// <inheritdoc cref="IAttachmentProcessor.ResourceName" />
+		public Field ResourceName { get; set; }
+
 		protected override string Name => "attachment";
 	}
 
@@ -91,6 +100,7 @@ public class AttachmentProcessorDescriptor<T>
 		Field IAttachmentProcessor.IndexedCharactersField { get; set; }
 		IEnumerable<string> IAttachmentProcessor.Properties { get; set; }
 		Field IAttachmentProcessor.TargetField { get; set; }
+		Field IAttachmentProcessor.ResourceName { get; set; }
 
 		/// <inheritdoc cref="IAttachmentProcessor.Field" />
 		public AttachmentProcessorDescriptor<T> Field(Field field) => Assign(field, (a, v) => a.Field = v);
@@ -122,5 +132,11 @@ public AttachmentProcessorDescriptor<T> IndexedCharactersField<TValue>(Expressio
 
 		/// <inheritdoc cref="IAttachmentProcessor.Properties" />
 		public AttachmentProcessorDescriptor<T> Properties(params string[] properties) => Assign(properties, (a, v) => a.Properties = v);
+
+		/// <inheritdoc cref="IAttachmentProcessor.ResourceName" />
+		public AttachmentProcessorDescriptor<T> ResourceName(Field field) => Assign(field, (a, v) => a.ResourceName = v);
+
+		/// <inheritdoc cref="IAttachmentProcessor.TargetField" />
+		public AttachmentProcessorDescriptor<T> ResourceName<TValue>(Expression<Func<T, TValue>> objectPath) => Assign(objectPath, (a, v) => a.ResourceName = v);
 	}
 }

tests/Tests/Ingest/ProcessorAssertions.cs

@@ -463,6 +463,39 @@ public class Attachment : ProcessorAssertion
 			public override string Key => "attachment";
 		}
 
+		[SkipVersion("<7.11.0", "Resource name support was added in 7.11")]
+		public class Attachment_WithResourceName : ProcessorAssertion
+		{
+			public override Func<ProcessorsDescriptor, IPromise<IList<IProcessor>>> Fluent => d => d
+				.Attachment<Project>(ud => ud
+					.Field(p => p.Description)
+					.IndexedCharacters(100_000)
+					.Properties("title", "author")
+					.IgnoreMissing()
+					.ResourceName(n => n.Name)
+				);
+
+			public override IProcessor Initializer => new AttachmentProcessor
+			{
+				Field = "description",
+				Properties = new[] { "title", "author" },
+				IndexedCharacters = 100_000,
+				IgnoreMissing = true,
+				ResourceName = "name"
+			};
+
+			public override object Json => new
+			{
+				field = "description",
+				ignore_missing = true,
+				properties = new[] { "title", "author" },
+				indexed_chars = 100_000,
+				resource_name = "name"
+			};
+
+			public override string Key => "attachment";
+		}
+
 		[SkipVersion("<7.4.0", "Circle processor added in 7.4.0")]
 		public class Circle : ProcessorAssertion
 		{